June 20, 2021
Making a case for handheld LIBS in mineral exploration
Recent studies with Dr. Cécile Fabre
Dr. Cécile Fabre, assistant professor at GeoRessources lab, is head of the Earth Sciences Department of Université de Lorraine and responsible for Master of Geosciences. She has been working on LIBS applications for mineral exploration since the end of the '90s and has a dedicated team for spectroscopic tools. Throughout the years, Dr. Fabre has used LIBS in and out of her classroom, from collecting data on drill cores with students to analyzing pegmatites in Portugal. Before working with SciAps handheld LIBS, Dr. Fabre worked with a laboratory LIBS. When she started looking for a handheld, SciAps Z-300 analyzer had all the features the team needed.
“The portability, size, weight, interface and large wavelength allowed us access to carbon (for soil analyses) and its integrated software program Profile Builder,” says Fabre.
In their presentation “Application of handheld laser-induced breakdown spectroscopy (LIBS) to quantitative analysis of carbonate minerals” to the International Online Meeting on Laser Induced Breakdown Spectroscopy in July 2020, the team concluded that
“this study demonstrates that LIBS is effectively applicable to the determination of carbonates and quantification of the carbonate mixtures.”
Primarily, Dr. Fabre and her team use handheld LIBS for the rapid analysis of specific minerals on samples taken from the field, usually before any other expensive analysis, to detect the presence of elements such as metals. A recent paper providing technical and spectroscopic support for lithium detection, "Analyses of Li-Rich Minerals Using Handheld LIBS Tool," found that the high resolution of the spectrometers combined with the low detection limits for light elements make the LIBS technique a powerful option to detect Li and trace elements of first interest, such as Be, Cs, F, and Rb. The LIBS spectra dataset combined with the Li content dataset can be used to obtain quantitative estimation of Li in Li-rich matrices.
In another presentation, “Investigation of the Handheld LIBS in terms of heavy metal detection in contaminated soil,” from September 2020, their work emphasized the critical issue of soil that is contaminated with heavy metals and how using handheld LIBS simplifies the necessary qualitative and quantitative analysis. The team concluded that
“Handheld Laser-induced breakdown spectroscopy (LIBS) device is able to perform real-time determination in the field with limited sample pre-treatment of permitting accurate, and faster analyses than the other conventional techniques.”
Exploration continues this year on the use of handheld LIBS for targeting pegmatic Li-ores by cross-referencing lightweight ground and airborne techniques on the same mission (LIGHTS project, http://lights.univ-lorraine.fr/).
References
To follow Dr. Fabre’s work, go to: https://www.researchgate.net/profile/Cecile-Fabre-3.
Presentation: “Investigation of the Handheld LIBS in terms of heavy metal detection in contaminated soil”
From abstract: “Contaminated soil with heavy metals is considered as one of the most critical environmental issues. Regarding heavy metals analysis, traditional analytical approaches such as atomic absorption spectrometry, inductively coupled plasma atomic emission spectroscopy, ICP-optical emission spectroscopy and ICP-mass spectroscopy have been widely used. Due to the complexity of those approaches, in the recent decade method of Laser-Induced Breakdown Spectroscopy has been more investigated with the relevant simplification concerning qualitative and quantitative analysis.”
From abstract: “Handheld Laser-induced breakdown spectroscopy (LIBS) device is able to perform real-time determination in the field with limited sample pre-treatment of permitting accurate, and faster analyses than the other conventional techniques. In this study, natural carbonate standards of calcite structure were analysed to investigate the spectral applicability for both mineral discrimination and quantitative analysis in Ca-Mg-Fe-Mn carbonate system.”
Article: “Advances in Laser-Induced Breakdown Spectroscopy analysis for geology: A critical review”
From abstract: “The review focuses on the most relevant advances and is reported in different sections relative to the analyzed objects (identification of rocks/minerals and sourcing; resources applications; slurry and drill cores; rare earth elements; light elements). . . . Therefore, the recent development of LIBS imaging should quickly lead to the implementation of LIBS imaging systems in the analytical laboratories worldwide in charge of analyzing geological samples.”
